Shape memory substances are able to be deformed into a temporary configuration and then restored to the original parent geometry by application of stimuli such as temperature, light, force, chemicals and electrical. The thermally induced shape-memory effect has been described for different material classes: polymers, such as polyurethranes, poly(styrene-block-butadiene) and polynorbornene, hydrogels, metallic alloys, and ceramics. Shape-memory alloys such as nickel-titanium have been widely used since the 1930s in robots, satellites, medical devices, actuators and other areas.
First introduced in Japan and then the United States in 1984, shape-memory polymers (SMP) have been used in the biomedical area for medical stents and sutures. Unlike shape-memory alloys, SMP have improved properties such as easy shaping, high shape stability, and adjustable transition temperature. Above their transition temperature (Ttrans), SMP cars be stretched, folded, or otherwise conformed to other shapes, tolerating up to 200% elongation. The process can be repeated many tunes without losing material integrity. The “memory” or recovery comes from the stored mechanical energy attained during the reconfiguration and cooling of the material. Some SMP recover shape not by heat but by changes in pH, electrical stimuli, or light stimuli. Some SMP are based on styrene acrylate, cyanate ester, and epoxy polymer systems.
SMP have been used in hair styling products for hair setting and skin and face makeup products for bioactive delivery. WO Publication No. 2003084489 and EP Patent No. 1682602 to Mnemoscience GmbH describe a hair care composition comprising SMP, alone or combined with cationic active ingredients to shape hair. JP 07126125 and U.S. Pat. No. 5,155,199 to Mitsubishi Heavy Industries Ltd. describe a cosmetic makeup composition containing shape-memory resin (polyurethane) spherical particles having a glass transition temperature lower than the skin surface temperature. However, SMP have not been used in other cosmetic products, such as mascaras, face-lifting skin masks or wrinkle reducing creams.
For example, mascara products have been marketed that curl or branch eyelashes. Unfortunately, eyelash curling and branching are difficult to achieve, requiring polymer film formers and fibers, and the effects are of short duration and lost under external influences such as eye blinking, high humidity, or contact with tears. Moreover, scissor type devices for curling eyelashes require a crimping process which both requires dexterity to result in a satisfactory crimp and which may result in pinching of fee eyelid, pulling and overcurling. Heating the eyelash curling device via a remote heating device such as a blow dryer has been used to curl the eyelashes more easily and permanently with these devices. Plunger type devices for curling eyelashes cannot be used by one hand and are designed for a person to perform the curling treatment on someone else.
Novel, safe and effective topical mascara compositions for curling or branching eyelashes are needed. The need exists for alternative methods to provide eyelash curling and branching which overcomes the problems associated with previous methods and compositions and which would represent a significant advance in cosmetic art.
The present invention provides for the use of SMP in mascaras, skin-lifting mask or lotion cosmetic compositions. None of the existing art provides the advantages and benefits of the present invention.
It is an object of the present invention to provide long-lasting ending or branching mascara compositions containing SMP.
It is another object of the present invention to provide face mask or face lifting compositions containing SMP.
It is yet another object of the present invention to provide a mascara composition containing a SMP, at least one wax and at least one film-forming polymer.
It is yet another object of the present invention to provide a skin lifting mask or lotion composition containing a SMP, an oil phase and a water phase.
It is a further object of the present invention to provide a method for curling eyelashes comprising applying the composition containing a SMP to the eyelashes.
It is a further object of the present invention to provide a method for producing a skin-lifting effect comprising applying the composition containing a SMP to the skin.